CA2773376C - Mobile roof safety device - Google Patents
Mobile roof safety device Download PDFInfo
- Publication number
- CA2773376C CA2773376C CA2773376A CA2773376A CA2773376C CA 2773376 C CA2773376 C CA 2773376C CA 2773376 A CA2773376 A CA 2773376A CA 2773376 A CA2773376 A CA 2773376A CA 2773376 C CA2773376 C CA 2773376C
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- CA
- Canada
- Prior art keywords
- secured
- roof
- gripping
- weighted base
- safety device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 230000015572 biosynthetic process Effects 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims abstract description 11
- 230000000712 assembly Effects 0.000 claims description 30
- 238000000429 assembly Methods 0.000 claims description 30
- 238000006073 displacement reaction Methods 0.000 claims description 18
- 239000002184 metal Substances 0.000 claims description 13
- 210000000078 claw Anatomy 0.000 claims description 12
- 239000007787 solid Substances 0.000 claims description 12
- 230000002093 peripheral effect Effects 0.000 claims description 5
- 230000000452 restraining effect Effects 0.000 abstract description 4
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 238000005755 formation reaction Methods 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- VJYFKVYYMZPMAB-UHFFFAOYSA-N ethoprophos Chemical compound CCCSP(=O)(OCC)SCCC VJYFKVYYMZPMAB-UHFFFAOYSA-N 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B35/00—Safety belts or body harnesses; Similar equipment for limiting displacement of the human body, especially in case of sudden changes of motion
- A62B35/0043—Lifelines, lanyards, and anchors therefore
- A62B35/0068—Anchors
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
- E04G21/32—Safety or protective measures for persons during the construction of buildings
- E04G21/3204—Safety or protective measures for persons during the construction of buildings against falling down
- E04G21/3223—Means supported by building floors or flat roofs, e.g. safety railings
- E04G21/3233—Means supported by building floors or flat roofs, e.g. safety railings without permanent provision in the floor or roof
- E04G21/3238—Means supported by building floors or flat roofs, e.g. safety railings without permanent provision in the floor or roof using counterweights
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
- E04G21/32—Safety or protective measures for persons during the construction of buildings
- E04G21/3261—Safety-nets; Safety mattresses; Arrangements on buildings for connecting safety-lines
- E04G21/3276—Arrangements on buildings for connecting safety-lines
Abstract
A mobile roof safety device and method of use for arresting the fall of a roof worker off an elevated flat roof is described. The mobile device comprises a displaceable frame having a weighted base adapted to be positioned on a flat roof surface for restraining a load. At least one actuable surface gripping assembly having a pivoting arm to which a safety line is attached for the engagement of a gripping formation secured to a lower end of the pivoting arm is secured to the weighted base. When a pulling force is applied on the pivot arm by a worker attached to the safety line secured to the pivot arm, the gripping formation is biased in the flat roof surface adjacent the weighted base to arrest the fall of the worker secured to the safety line with the weight of the weighted base providing additional restraint against the pulling force on the safety line.
Description
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MOBILE ROOF SAFETY DEVICE
TECHNICAL FIELD
The present invention relates to a mobile roof safety device for use on BACKGROUND ART
Various safety apparatuses are used and to which roof workers can be attached to arrest the fall of a worker off the roof. Many of these devices are used for pitch roofs and wherein the worker is fitted with a harness to which a safety line with an energy absorbing locking mechanism is secured and attached to the device. The safety apparatus is usually retained on the roof by fasteners secured into the roof at a It is a feature of the present invention to provide a mobile roof safety device for use on substantially flat roofs for the safety of workers and which is capable of securing at least one and preferably at least two or more worker safety lines may be attached and which substantially overcomes the above-mentioned disadvantages of the
MOBILE ROOF SAFETY DEVICE
TECHNICAL FIELD
The present invention relates to a mobile roof safety device for use on BACKGROUND ART
Various safety apparatuses are used and to which roof workers can be attached to arrest the fall of a worker off the roof. Many of these devices are used for pitch roofs and wherein the worker is fitted with a harness to which a safety line with an energy absorbing locking mechanism is secured and attached to the device. The safety apparatus is usually retained on the roof by fasteners secured into the roof at a It is a feature of the present invention to provide a mobile roof safety device for use on substantially flat roofs for the safety of workers and which is capable of securing at least one and preferably at least two or more worker safety lines may be attached and which substantially overcomes the above-mentioned disadvantages of the
- 2 -Another feature of the present invention is to provide a method of arresting the fall of a roof worker off an elevated flat roof using the mobile roof safety device of the invention which substantially overcomes the above-mentioned disadvantages of the prior art.
Another feature of the present invention is to provide a mobile roof safety device which has a weighted base of sufficient weight for travel restraint of roof workers.
Another feature of the present invention is to provide a mobile roof safety device having a weighted base adapted to be lowered onto the surface of a roof and to which is secured one or more actuable surface gripping assemblies, each of which is adapted to receive a life line and wherein the gripping assembly is engaged in the roof surface upon the fall of a worker off the roof to arrest the worker's fall together with the weighted base.
According to the above features, from a broad aspect, the present invention provides a mobile roof safety device for use on substantially flat roofs for the safety of workers. The roof safety device comprises a displaceable frame having a weighted base adapted to be positioned on a flat roof surface for restraining a load.
Retractable frame displacement means is secured to the frame for displacing the frame on the flat roof surface with the weighted base elevated therefrom. At least one actuable roof surface gripping means is secured in a lower portion of the frame above the weighted base. A safety line attachment means is secured to the roof surface gripping means. Restoring means is provided to maintain the actuable roof surface gripping means a disengaged position. The roof surface gripping means is disposed spaced above the roof surface when the weighted base is lowered onto the flat roof surface whereby when a pulling force is applied to the safety line attachment means by a line attached to a worker falling off the roof, the roof surface gripping means is biased in the flat roof surface adjacent the weighted base to arrest the worker secured to the safety line with the weight of the weighted base providing additional restraint against the pulling force on the safety line.
According to a further broad aspect of the present invention there is provided a method of arresting the fall of a roof worker falling off an elevated flat roof.
The method comprises: i) positioning a mobile roof safety device having a displaceable frame with a weighted base on the roof; ii) displacing the mobile roof safety device to a safe position of use; iii) retracting frame displacement means to lower the weighted base on the roof; iv) attaching a safety line to an actuable roof surface gripping means secured to the weighted base, the safety line being secured to =
Another feature of the present invention is to provide a mobile roof safety device which has a weighted base of sufficient weight for travel restraint of roof workers.
Another feature of the present invention is to provide a mobile roof safety device having a weighted base adapted to be lowered onto the surface of a roof and to which is secured one or more actuable surface gripping assemblies, each of which is adapted to receive a life line and wherein the gripping assembly is engaged in the roof surface upon the fall of a worker off the roof to arrest the worker's fall together with the weighted base.
According to the above features, from a broad aspect, the present invention provides a mobile roof safety device for use on substantially flat roofs for the safety of workers. The roof safety device comprises a displaceable frame having a weighted base adapted to be positioned on a flat roof surface for restraining a load.
Retractable frame displacement means is secured to the frame for displacing the frame on the flat roof surface with the weighted base elevated therefrom. At least one actuable roof surface gripping means is secured in a lower portion of the frame above the weighted base. A safety line attachment means is secured to the roof surface gripping means. Restoring means is provided to maintain the actuable roof surface gripping means a disengaged position. The roof surface gripping means is disposed spaced above the roof surface when the weighted base is lowered onto the flat roof surface whereby when a pulling force is applied to the safety line attachment means by a line attached to a worker falling off the roof, the roof surface gripping means is biased in the flat roof surface adjacent the weighted base to arrest the worker secured to the safety line with the weight of the weighted base providing additional restraint against the pulling force on the safety line.
According to a further broad aspect of the present invention there is provided a method of arresting the fall of a roof worker falling off an elevated flat roof.
The method comprises: i) positioning a mobile roof safety device having a displaceable frame with a weighted base on the roof; ii) displacing the mobile roof safety device to a safe position of use; iii) retracting frame displacement means to lower the weighted base on the roof; iv) attaching a safety line to an actuable roof surface gripping means secured to the weighted base, the safety line being secured to =
- 3 -an attachment secured to the roof surface gripping means which is maintained at a disengaged position by spring restoring means; and v) engaging the roof surface gripping means into the roof surface upon a load applied to the safety line overcoming a restoring means of the roof surface gripping means.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a mobile roof safety device constructed in accordance with the present invention;
FIG. 2 is a side view of Figure 1;
FIG. 3 is a top view of Figure 1;
FIG. 4 is a bottom view of Figure 1;
FIG. 5 is a side view of the frame of the mobile roof safety device of Figure 1;
FIG. 6A is a side view of the pivoting arm of the actuable surface gripping assembly;
FIG. 6B is a further side view of the pivoting arm;
FIG. 7 is a fragmented end view of the lower portion of the mobile roof safety device illustrating the assembly of the actuable roof surface gripping means to the weighted base of the device;
FIG. 8 is a perspective view showing a modification of the actuable roof surface gripping assembly;
FIG. 9A is a side view of the pivotal displacement arm with its fork end secured to the support arms of the front wheel;
FIG. 9B is a front view of Figure 9A;
FIG. 10 is a schematic illustration demonstrating the use of the mobile roof safety device of the present invention; and FIG. 11 is a plan view of an angle indicator decal which is affixed to the top surface of the weighted base and in relationship with one or more actuable roof surface gripping assembly.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings and more particularly to Figures 1 to 5, there is shown generally at 10 the mobile roof safety device of the present invention.
As shown in Figure 10, the mobile roof safety device 10 is for use on substantially flat
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a mobile roof safety device constructed in accordance with the present invention;
FIG. 2 is a side view of Figure 1;
FIG. 3 is a top view of Figure 1;
FIG. 4 is a bottom view of Figure 1;
FIG. 5 is a side view of the frame of the mobile roof safety device of Figure 1;
FIG. 6A is a side view of the pivoting arm of the actuable surface gripping assembly;
FIG. 6B is a further side view of the pivoting arm;
FIG. 7 is a fragmented end view of the lower portion of the mobile roof safety device illustrating the assembly of the actuable roof surface gripping means to the weighted base of the device;
FIG. 8 is a perspective view showing a modification of the actuable roof surface gripping assembly;
FIG. 9A is a side view of the pivotal displacement arm with its fork end secured to the support arms of the front wheel;
FIG. 9B is a front view of Figure 9A;
FIG. 10 is a schematic illustration demonstrating the use of the mobile roof safety device of the present invention; and FIG. 11 is a plan view of an angle indicator decal which is affixed to the top surface of the weighted base and in relationship with one or more actuable roof surface gripping assembly.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings and more particularly to Figures 1 to 5, there is shown generally at 10 the mobile roof safety device of the present invention.
As shown in Figure 10, the mobile roof safety device 10 is for use on substantially flat
- 4 -elevated roofs 11 of building structures 12 whereby to prevent roof workers 13 secured to the device 10 of the present invention by safety lines 14 from falling off the roof. A
worker, such as worker 13", which falls of the roof is arrested by the device 10 before reaching the ground surface.
The mobile roof safety device 10 comprises a displaceable frame 15, as shown in Figure 5, and which is provided with a weighted base 16 which is adapted to be lowered onto the flat roof surface 11, as shown in Figure 10, and provides a dead load for travel restraint of one or more roof workers attached thereto.
Retractable frame displacement means in the form of wheel assemblies 17 are secured to the displaceable frame 15 and adapted to displace the frame with the weighted base elevated by the wheel assemblies. The weighted base is also lowered onto the roof surface by these wheel assemblies, as will be described later.
The mobile roof safety device 10 of the present invention is also provided with at least one actuable roof surface gripping means or assembly 18, herein two being shown and identical to one another and which are secured in a lower portion of the frame, herein to the top surface of the weighted base 16. The weighted base 16 is a solid metal plate provided with a flat bottom surface 20, as shown in Figure 4. The solid metal plate has a predetermined weight in relation to the load to be connected thereto. In the particular embodiment hereinshown, the total weight of the mobile safety device weighs approximately 1000 pounds.
As also hereinshown, the surface gripping assemblies 18 are secured to a common side edge 21 of the weighted base 16 adjacent a work zone..
As more clearly shown in Figure 1 and with further reference to Figures 6A and 6B, the actuable surface gripping assemblies 18 comprise a pivoting arm 25, herein a tubular arm of square cross-section constructed of steel and pivotally secured between a pair of spaced-apart parallel flanges 26, as better seen in Figure
worker, such as worker 13", which falls of the roof is arrested by the device 10 before reaching the ground surface.
The mobile roof safety device 10 comprises a displaceable frame 15, as shown in Figure 5, and which is provided with a weighted base 16 which is adapted to be lowered onto the flat roof surface 11, as shown in Figure 10, and provides a dead load for travel restraint of one or more roof workers attached thereto.
Retractable frame displacement means in the form of wheel assemblies 17 are secured to the displaceable frame 15 and adapted to displace the frame with the weighted base elevated by the wheel assemblies. The weighted base is also lowered onto the roof surface by these wheel assemblies, as will be described later.
The mobile roof safety device 10 of the present invention is also provided with at least one actuable roof surface gripping means or assembly 18, herein two being shown and identical to one another and which are secured in a lower portion of the frame, herein to the top surface of the weighted base 16. The weighted base 16 is a solid metal plate provided with a flat bottom surface 20, as shown in Figure 4. The solid metal plate has a predetermined weight in relation to the load to be connected thereto. In the particular embodiment hereinshown, the total weight of the mobile safety device weighs approximately 1000 pounds.
As also hereinshown, the surface gripping assemblies 18 are secured to a common side edge 21 of the weighted base 16 adjacent a work zone..
As more clearly shown in Figure 1 and with further reference to Figures 6A and 6B, the actuable surface gripping assemblies 18 comprise a pivoting arm 25, herein a tubular arm of square cross-section constructed of steel and pivotally secured between a pair of spaced-apart parallel flanges 26, as better seen in Figure
5, which are welded on the top surface 19 of the weighted base adjacent the edge 21.
The pivoting arm 25 is provided with a gripping formation constituted by a gripping plate 27 having a lower claw edge 28 provided with a series of pointed teeth 29 whereby to engage into the roof surface 11. At the other end of the pivoting arm 25, there is provided a safety line attachment ring 30 which is welded to the pivoting arm 30. At the top end of the pivoting arm 25 there is also provided a spring attachment bracket 31 to which a helical spring 32 is secured, see Figure 1. The other end of the helical spring 32 is attached to a further bracket 33 mounted on the top surface 19 of the weighted base 16. The helical spring constitutes a restoring means to maintain the pivoting arm at a disengaged position, as better shown in Figure 7.
=
As shown in Figure 7, the gripping plate 27 has its pointed teeth 29 disposed spaced closely above the roof surface 11 whereby when a pulling force is applied to the pivot arm, in the direction of arrow 35 by the safety line 14 secured thereto and caused by a worker attached to the safety line and falling off the roof, the pivoting arm will pivot forward on its pivot connection 34 and cause the pointed teeth 29 of the claw edge to immediately engage into the roof surface 11. The arresting means of the gripping plate in combination with the weighted base will immediately provide a rigid connection and dead load to arrest the fall of the worker.
As shown in Figures 1 to 4, there are two surface gripping assemblies 18 secured adjacent the common edge 21 and these are spaced-apart from one another.
The side edge 21 of the weighted base 16 is provided with recesses 37 to accommodate each of the surface gripping assemblies 18. Accordingly, the claw edge of the gripping plate 27 is engaged into the roof surface substantially in line with the common edge 21 of the weighted base. Therefore, the combined arresting force provided by the surface gripping assembly and the weighted base disposed onto the roof to provide a low center of gravity connection to prevent toppling of the mobile safety device 10 by the pulling force which is substantially in a plane close to the roof surface. This restraining force is calculated to exceed a total load which may be connected onto the mobile safety device by two workers simultaneously falling off the roof.
With reference now to Figure 8, there is shown a modification of the actuable roof gripping assembly, herein assembly 18'. The modification is constituted in that a second gripping plate 27' is secured to the lower end portion 39 of the pivoting arm 25 and disposed above the angulated gripping plate 27. This second gripping plate 27' extends substantially co-extensively with the pivoting arm 25 and provides further arresting means to meet different regulatory specifications. In order to engage the second gripping plate 27' into the roof surface, the load would have to cause the first gripping plate 27 to engage into the roof and then cause the pivoting arm 25 to continue pivoting on its pivot connection 34 and lift the weighted base 16 which would apply a load onto the pointed teeth 29 of the claw edge of the lower gripping plate 27 to further penetrate into the roof surface.
As shown in Figure 8, a bridge arm 40 is secured over the second gripping plate 27' above the recess 37 to protect a safety line secured to the attachment ring 30 from contacting the claw edge 28' of the second gripping plate 27' and be damaged or severed. It is pointed out that the safety lines 14 as illustrated in Figure 10 for use with roof workers having to work on edges of roofs are usually provided with an = =
The pivoting arm 25 is provided with a gripping formation constituted by a gripping plate 27 having a lower claw edge 28 provided with a series of pointed teeth 29 whereby to engage into the roof surface 11. At the other end of the pivoting arm 25, there is provided a safety line attachment ring 30 which is welded to the pivoting arm 30. At the top end of the pivoting arm 25 there is also provided a spring attachment bracket 31 to which a helical spring 32 is secured, see Figure 1. The other end of the helical spring 32 is attached to a further bracket 33 mounted on the top surface 19 of the weighted base 16. The helical spring constitutes a restoring means to maintain the pivoting arm at a disengaged position, as better shown in Figure 7.
=
As shown in Figure 7, the gripping plate 27 has its pointed teeth 29 disposed spaced closely above the roof surface 11 whereby when a pulling force is applied to the pivot arm, in the direction of arrow 35 by the safety line 14 secured thereto and caused by a worker attached to the safety line and falling off the roof, the pivoting arm will pivot forward on its pivot connection 34 and cause the pointed teeth 29 of the claw edge to immediately engage into the roof surface 11. The arresting means of the gripping plate in combination with the weighted base will immediately provide a rigid connection and dead load to arrest the fall of the worker.
As shown in Figures 1 to 4, there are two surface gripping assemblies 18 secured adjacent the common edge 21 and these are spaced-apart from one another.
The side edge 21 of the weighted base 16 is provided with recesses 37 to accommodate each of the surface gripping assemblies 18. Accordingly, the claw edge of the gripping plate 27 is engaged into the roof surface substantially in line with the common edge 21 of the weighted base. Therefore, the combined arresting force provided by the surface gripping assembly and the weighted base disposed onto the roof to provide a low center of gravity connection to prevent toppling of the mobile safety device 10 by the pulling force which is substantially in a plane close to the roof surface. This restraining force is calculated to exceed a total load which may be connected onto the mobile safety device by two workers simultaneously falling off the roof.
With reference now to Figure 8, there is shown a modification of the actuable roof gripping assembly, herein assembly 18'. The modification is constituted in that a second gripping plate 27' is secured to the lower end portion 39 of the pivoting arm 25 and disposed above the angulated gripping plate 27. This second gripping plate 27' extends substantially co-extensively with the pivoting arm 25 and provides further arresting means to meet different regulatory specifications. In order to engage the second gripping plate 27' into the roof surface, the load would have to cause the first gripping plate 27 to engage into the roof and then cause the pivoting arm 25 to continue pivoting on its pivot connection 34 and lift the weighted base 16 which would apply a load onto the pointed teeth 29 of the claw edge of the lower gripping plate 27 to further penetrate into the roof surface.
As shown in Figure 8, a bridge arm 40 is secured over the second gripping plate 27' above the recess 37 to protect a safety line secured to the attachment ring 30 from contacting the claw edge 28' of the second gripping plate 27' and be damaged or severed. It is pointed out that the safety lines 14 as illustrated in Figure 10 for use with roof workers having to work on edges of roofs are usually provided with an = =
- 6 -energy absorbing mechanism 14', well known in the art, whereby to absorb the load on the safety line caused by a worker falling off a roof and to lock on to the life line.
As shown in Figures 1, 2 and 5, there is further provided safety line connectors 41 secured to a pair of vertical posts 42 of the frame and secured to the top surface 19 of the weighted base and above the actuable roof gripping assemblies 18.
These safety line connectors 41 are provided for the connection of safety lines of predetermined lengths to restrict the displacement of a worker in a restrained work zone delineated adjacent the mobile roof safety device 10 and spaced from the peripheral edges of a flat roof. This provides security to workers that are not permitted As shown in Figures 3, 10 and 11, an angle indicator decal 45 is affixed to the top surface 19 of the weighted base 16 between the actuable roof gripping assemblies 18 and adjacent the common edge 21 to indicate the angle of displacement of roof workers attached to the actuable roof gripping assemblies 18. As shown in As previously described, the wheel assemblies 17 constitute a retractable frame displacement means. These wheel assemblies 17 are better illustrated in Figures 1 and 2 and as shown therein, there are two wheel assemblies 17 in a rear portion of the frame 15 an a single central wheel assembly 17' in a front
As shown in Figures 1, 2 and 5, there is further provided safety line connectors 41 secured to a pair of vertical posts 42 of the frame and secured to the top surface 19 of the weighted base and above the actuable roof gripping assemblies 18.
These safety line connectors 41 are provided for the connection of safety lines of predetermined lengths to restrict the displacement of a worker in a restrained work zone delineated adjacent the mobile roof safety device 10 and spaced from the peripheral edges of a flat roof. This provides security to workers that are not permitted As shown in Figures 3, 10 and 11, an angle indicator decal 45 is affixed to the top surface 19 of the weighted base 16 between the actuable roof gripping assemblies 18 and adjacent the common edge 21 to indicate the angle of displacement of roof workers attached to the actuable roof gripping assemblies 18. As shown in As previously described, the wheel assemblies 17 constitute a retractable frame displacement means. These wheel assemblies 17 are better illustrated in Figures 1 and 2 and as shown therein, there are two wheel assemblies 17 in a rear portion of the frame 15 an a single central wheel assembly 17' in a front
- 7 -cylinder whereby the wheels can be lifted above the flat roof surface 11 to position the weighted base thereon or lowered to lift the weighted base 16 off the work surface whereby to displace the mobile roof safety device 10.
With further reference now to Figures 9A and 9B, there is shown the construction of a pivotal displacement tow arm 60 which comprises a rod 61 having handle grips 62 at a free end thereof. The tow rod 61 has a fork formation 63 formed at a lower end thereof and defined by a pair of opposed parallel branch arms 64 to be pivotally at a top end of the wheel support bracket 65 on pivot 61'. The wheel 55 is secured at a lower end of the bracket 65 by its axle 66. Accordingly, the pivotal displacement arm 60 can be hinged forwardly in the direction of arrow 67 whereby to pull the mobile roof safety device 10 onto the roof surface to position it at a desired location. The fork bracket 63 also acts as a brake for engaging the top surface 55' of the front wheel 55, as shown in Figure 9A, when hinged forwardly downwards in the direction of arrow 67 whereby to prevent movement of the mobile roof safety device when left on a roof with the weighted base 16 retracted. It is pointed out that for very large roofs such as high-rise buildings, it may be preferable to leave a mobile roof safety device 10 permanently on the roof and this feature therefore arrests the device at a desired stored location.
In order to elevate the mobile roof safety device 10 to a roof it is necessary to use a crane and for this purpose a lifting bar 70 is part of the frame and secured to the vertical posts 42 and provided with attachment steel loops or rings 71 to engage the device to a crane hoist cable. As also shown in Figure 1, the mobile safety device is provided with a document storing tube 72 whereby to provide a manual of operation readily accessible to workers to instruct the worker on the use of the device and its safety features.
The mobile roof safety device 10 provides for a method of arresting the fall of a roof worker off an elevated flat roof and this method essentially consists in positioning the Mobile roof safety device 10 with the wheels retracted. The wheels 54 and 55 are retracted so that one or more roof workers can attach their safety line to one of the actuable surface gripping assemblies 18 if he is to work close to the peripheral edge 11' of the roof or to the safety line connectors 41 if he is to work in a zone spaced from the peripheral edge 11' of a roof. It is pointed out that there may be several workers on the roof working in different zones, some close to the edge and some spaced form the edge of the roof and therefore they each connect to appropriate ones of either the actuable roof gripping assemblies 18 or the safety line connectors 41. If a roof worker was to fall of the edge of the roof, it would automatically engage the = .
With further reference now to Figures 9A and 9B, there is shown the construction of a pivotal displacement tow arm 60 which comprises a rod 61 having handle grips 62 at a free end thereof. The tow rod 61 has a fork formation 63 formed at a lower end thereof and defined by a pair of opposed parallel branch arms 64 to be pivotally at a top end of the wheel support bracket 65 on pivot 61'. The wheel 55 is secured at a lower end of the bracket 65 by its axle 66. Accordingly, the pivotal displacement arm 60 can be hinged forwardly in the direction of arrow 67 whereby to pull the mobile roof safety device 10 onto the roof surface to position it at a desired location. The fork bracket 63 also acts as a brake for engaging the top surface 55' of the front wheel 55, as shown in Figure 9A, when hinged forwardly downwards in the direction of arrow 67 whereby to prevent movement of the mobile roof safety device when left on a roof with the weighted base 16 retracted. It is pointed out that for very large roofs such as high-rise buildings, it may be preferable to leave a mobile roof safety device 10 permanently on the roof and this feature therefore arrests the device at a desired stored location.
In order to elevate the mobile roof safety device 10 to a roof it is necessary to use a crane and for this purpose a lifting bar 70 is part of the frame and secured to the vertical posts 42 and provided with attachment steel loops or rings 71 to engage the device to a crane hoist cable. As also shown in Figure 1, the mobile safety device is provided with a document storing tube 72 whereby to provide a manual of operation readily accessible to workers to instruct the worker on the use of the device and its safety features.
The mobile roof safety device 10 provides for a method of arresting the fall of a roof worker off an elevated flat roof and this method essentially consists in positioning the Mobile roof safety device 10 with the wheels retracted. The wheels 54 and 55 are retracted so that one or more roof workers can attach their safety line to one of the actuable surface gripping assemblies 18 if he is to work close to the peripheral edge 11' of the roof or to the safety line connectors 41 if he is to work in a zone spaced from the peripheral edge 11' of a roof. It is pointed out that there may be several workers on the roof working in different zones, some close to the edge and some spaced form the edge of the roof and therefore they each connect to appropriate ones of either the actuable roof gripping assemblies 18 or the safety line connectors 41. If a roof worker was to fall of the edge of the roof, it would automatically engage the = .
- 8 -gripping formation into the roof surface upon the load provided by the worker secured to the safety line and these gripping formations in combination with the load of the weighted base will provide a restraining load to arrest the fall of the worker.
It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.
It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.
Claims (24)
1. A mobile roof safety device for use on substantially flat roofs for the safety of workers, said roof safety device comprising:
a displaceable frame having a weighted base adapted to be positioned on a flat roof surface, said weighted base having opposed top and bottom surfaces, retractable wheel assemblies secured to said frame for displacing said frame on said flat roof surface with said bottom surface of said weighted base elevated therefrom, wherein said wheel assemblies each comprise:
pivotal wheel support arms pivotally engaged to the frame and supporting one or more wheels, and a jack pivotally engaged to the pivotal wheel support arms and pivotally engaged to the frame above and spaced apart from said top surface of said weighted base, said jack displacing said pivotal wheel support arms between a first position where said or more wheels protrude below said bottom surface of said weighted base to engage said flat roof surface and a second position where said or more wheels are above a plane defined by said bottom surface of said weighted base, at least one actuable roof surface gripping assembly secured in a lower portion of said frame above said bottom surface of said weighted base, said actuable roof surface gripping assembly being biased in a disengaged position, said roof surface gripping assembly in the disengaged position being disposed spaced above said plane defined by said bottom surface of said weighted base, and a safety line secured to said roof surface gripping assembly, wherein when a pulling force is applied to said safety line by a worker secured thereto falling off said roof, said roof surface gripping assembly moves away from the disengaged position and to an engaged position where part of the gripping assembly protrudes below said plane defined by said bottom surface of said weighted base, wherein with said wheel assemblies in the second position, said gripping assembly in the engaged position engages said flat roof surface adjacent said weighted base to arrest said worker secured to said safety line with the weight of said weighted base providing additional restraint against said pulling force on said safety line, and wherein one of said wheel assemblies is a front wheel assembly having a pivotal displacement tow arm pivotally secured at a fork end to said wheel support arms on a pivot axis, said one or more wheels including a front wheels secured between said wheel support arms, said pivot axis spaced above a wheel axis of said front wheel, said fork end engaging a tire of said wheel when said pivotal displacement arm is positioned at a predetermined forward and downward angle to constitute a brake for said wheel.
a displaceable frame having a weighted base adapted to be positioned on a flat roof surface, said weighted base having opposed top and bottom surfaces, retractable wheel assemblies secured to said frame for displacing said frame on said flat roof surface with said bottom surface of said weighted base elevated therefrom, wherein said wheel assemblies each comprise:
pivotal wheel support arms pivotally engaged to the frame and supporting one or more wheels, and a jack pivotally engaged to the pivotal wheel support arms and pivotally engaged to the frame above and spaced apart from said top surface of said weighted base, said jack displacing said pivotal wheel support arms between a first position where said or more wheels protrude below said bottom surface of said weighted base to engage said flat roof surface and a second position where said or more wheels are above a plane defined by said bottom surface of said weighted base, at least one actuable roof surface gripping assembly secured in a lower portion of said frame above said bottom surface of said weighted base, said actuable roof surface gripping assembly being biased in a disengaged position, said roof surface gripping assembly in the disengaged position being disposed spaced above said plane defined by said bottom surface of said weighted base, and a safety line secured to said roof surface gripping assembly, wherein when a pulling force is applied to said safety line by a worker secured thereto falling off said roof, said roof surface gripping assembly moves away from the disengaged position and to an engaged position where part of the gripping assembly protrudes below said plane defined by said bottom surface of said weighted base, wherein with said wheel assemblies in the second position, said gripping assembly in the engaged position engages said flat roof surface adjacent said weighted base to arrest said worker secured to said safety line with the weight of said weighted base providing additional restraint against said pulling force on said safety line, and wherein one of said wheel assemblies is a front wheel assembly having a pivotal displacement tow arm pivotally secured at a fork end to said wheel support arms on a pivot axis, said one or more wheels including a front wheels secured between said wheel support arms, said pivot axis spaced above a wheel axis of said front wheel, said fork end engaging a tire of said wheel when said pivotal displacement arm is positioned at a predetermined forward and downward angle to constitute a brake for said wheel.
2. The movable safety device as claimed in claim 1, wherein said weighted base is a solid metal plate having a flat bottom surface, said roof surface gripping assembly being secured to a top surface of said solid metal plate adjacent a side edge thereof, said solid metal plate having a predetermined weight creating a dead load.
3. The movable safety device as claimed in claim 2, wherein there is further provided an angle indicator secured to said solid metal plate adjacent said side edge and in relation to said actuable roof surface gripping assembly to indicate a safe working zone for said worker secured to said actuable surface gripping assembly by said safety line.
4. The movable safety device as claimed in claim 2 or 3, further comprising an additional roof surface gripping assembly, the roof surface gripping assemblies being spaced-apart from one another, said side edge of said solid metal plate having recesses therein for accommodating each surface gripping assembly.
5. The movable safety device as claimed in any one of claims 1 to 4, wherein said actuable roof surface gripping assembly comprises a pivoting arm secured to a pivot connection, a gripping formation at a lower end portion of said pivoting arm, said safety line being secured to said pivoting arm above said pivot connection.
6. The movable safety device as claimed in claim 5, wherein said pivoting arm is pivotally secured above the top surface of said weighted base adjacent a side edge thereof, said roof surface gripping assembly being biased in the disengaged position by a helical spring secured to a top end portion of said pivoting arm and to top surface of said weighted base.
7. The movable safety device as claimed in claim 5 or 6, wherein said gripping formation includes a gripping plate having a claw edge formed of pointed teeth, said gripping plate being secured to said lower end portion of said pivoting arm and disposed at a downward angle towards said flat roof surface.
8. The movable safety device as claimed in claim 5 or 6, wherein said gripping formation includes a first gripping plate having a claw edge formed of pointed teeth, said first gripping plate being secured to said lower end portion of said pivoting arm and disposed at a downward angle, and a second gripping plate secured to said lower end portion of said pivoting arm above said first gripping plate and extending substantially co-extensively with said pivoting arm, said second gripping plate also having a claw edge.
9. The movable safety device as claimed in claim 8, wherein a bridge arm is secured over said second gripping plate and secured above a recess accommodating said gripping assembly to protect said safety line from said claw edge of said second gripping plate.
10. The movable safety device as claimed in any one of claims 5 to 9, wherein said safety line comprises an energy absorbing locking mechanism which is actuated by a predetermined load, said safety line being attached to a metal attachment ring secured to said pivoting arm.
11. The movable safety device as claimed in any one of claims 1 to 10, wherein there is further provided safety line connection means immovably secured to said displaceable frame for the connection of safety lines of predetermined lengths relative to a restrained work zone delineated adjacent said mobile roof safety device and spaced from peripheral edges of said flat roof surface.
12. The movable safety device as claimed in any one of claims 1 to 11, wherein said jack is a hand operable jack having an extendible and retractable telescopic shaft secured at a bottom end to said wheel support arms, and a crank to displace said telescopic shaft.
13. A mobile roof safety device for use on substantially flat roofs for the safety of workers, said roof safety device comprising:
a displaceable frame having a weighted base adapted to be positioned on a flat roof surface, said weighted base having a bottom surface, retractable wheel assemblies secured to said frame for displacing said frame on said flat roof surface with said bottom surface of said weighted base elevated therefrom, said wheel assemblies secured to said frame, said wheel assemblies each comprising pivotal wheel support arms for supporting one or more wheels, said pivotal wheel support arms being displaceable to position said one or more wheels at a retracted position to lower said weighted base on said flat roof surface with said wheels spaced thereabove, and to an engaged position where said wheels are displaced below said bottom surface of said weighted base, at least one actuable roof surface gripping assembly secured in a lower portion of said frame above said weighted base, said actuable roof surface gripping assembly being biased in a disengaged position, said roof surface gripping assembly in the disengaged position being disposed spaced above a plane defined by said bottom surface of said weighted base, and a safety line secured to said roof surface gripping assembly, wherein when a pulling force is applied to said safety line by a worker secured thereto falling off said roof, said roof surface gripping assembly moves away from the disengaged position and to an engaged position where part of the gripping assembly protrudes below said plane defined by said bottom surface of said weighted base, wherein with the retractable wheel assemblies retracted such that said bottom surface of said weighted base rests against said flat roof surface, said gripping assembly in the engaged position engages said flat roof surface adjacent said weighted base to arrest said worker secured to said safety line with the weight of said weighted base providing additional restraint against said pulling force on said safety line, wherein one of said wheel assemblies is a front wheel assembly having a pivotal displacement tow arm pivotally secured at a fork end to said wheel support arms on a pivot axis, said one or more wheels including a front wheels secured between said wheel support arms, said pivot axis spaced above a wheel axis of said front wheel, said fork end engaging a tire of said wheel when said pivotal displacement arm is positioned at a predetermined forward and downward angle to constitute a brake for said wheel.
a displaceable frame having a weighted base adapted to be positioned on a flat roof surface, said weighted base having a bottom surface, retractable wheel assemblies secured to said frame for displacing said frame on said flat roof surface with said bottom surface of said weighted base elevated therefrom, said wheel assemblies secured to said frame, said wheel assemblies each comprising pivotal wheel support arms for supporting one or more wheels, said pivotal wheel support arms being displaceable to position said one or more wheels at a retracted position to lower said weighted base on said flat roof surface with said wheels spaced thereabove, and to an engaged position where said wheels are displaced below said bottom surface of said weighted base, at least one actuable roof surface gripping assembly secured in a lower portion of said frame above said weighted base, said actuable roof surface gripping assembly being biased in a disengaged position, said roof surface gripping assembly in the disengaged position being disposed spaced above a plane defined by said bottom surface of said weighted base, and a safety line secured to said roof surface gripping assembly, wherein when a pulling force is applied to said safety line by a worker secured thereto falling off said roof, said roof surface gripping assembly moves away from the disengaged position and to an engaged position where part of the gripping assembly protrudes below said plane defined by said bottom surface of said weighted base, wherein with the retractable wheel assemblies retracted such that said bottom surface of said weighted base rests against said flat roof surface, said gripping assembly in the engaged position engages said flat roof surface adjacent said weighted base to arrest said worker secured to said safety line with the weight of said weighted base providing additional restraint against said pulling force on said safety line, wherein one of said wheel assemblies is a front wheel assembly having a pivotal displacement tow arm pivotally secured at a fork end to said wheel support arms on a pivot axis, said one or more wheels including a front wheels secured between said wheel support arms, said pivot axis spaced above a wheel axis of said front wheel, said fork end engaging a tire of said wheel when said pivotal displacement arm is positioned at a predetermined forward and downward angle to constitute a brake for said wheel.
14. The movable safety device as claimed in claim 13, wherein said weighted base is a solid metal plate having a flat bottom surface, said roof surface gripping assembly being secured to a top surface of said solid metal plate adjacent a side edge thereof, said solid metal plate having a predetermined weight creating a dead load.
15. The movable safety device as claimed in claim 14, wherein there is further provided an angle indicator secured to said solid metal plate adjacent said side edge and in relation to said actuable roof surface gripping assembly to indicate a safe working zone for said worker secured to said actuable surface gripping assembly by said safety line.
16. The movable safety device as claimed in claim 14 or 15, further comprising an additional roof surface gripping assembly, the roof surface gripping assemblies being spaced-apart from one another, said side edge of said solid metal plate having recesses therein for accommodating each surface gripping assembly.
17. The movable safety device as claimed in any one of claims 13 to 16, wherein said actuable roof surface gripping assembly comprises a pivoting arm secured to a pivot connection, a gripping formation at a lower end portion of said pivoting arm, said safety line being secured to said pivoting arm above said pivot connection.
18. The movable safety device as claimed in claim 17, wherein said pivoting arm is pivotally secured above the top surface of said weighted base adjacent a side edge thereof, said roof surface gripping assembly being biased in the disengaged position by a spring secured to a top end portion of said pivoting arm and to said top surface of said weighted base.
19. The movable safety device as claimed in claim 17 or 18, wherein said gripping formation includes a first gripping plate having a claw edge formed of pointed teeth, said first gripping plate being secured to said lower end portion of said pivoting arm and disposed at a downward angle, and a second gripping plate secured to said lower end portion of said pivoting arm above said first gripping plate and extending substantially co-extensively with said pivoting arm, said second gripping plate also having a claw edge.
20. A movable safety device as claimed in claim 19, wherein a bridge arm is secured over said second gripping plate and secured above a recess accommodating said gripping assembly to protect said safety line from said claw edge of said second gripping plate.
21. A method of arresting a fall of a roof worker falling off an elevated flat roof, said method comprising the steps of:
i) positioning a mobile roof safety device having a displaceable frame with a weighted base on said roof;
ii) displacing said mobile roof safety device to a safe position of use;
iii) retracting frame displacement means to lower said weighted base on said roof;
iv) attaching a safety line to an actuable roof surface gripping means secured to said weighted base, said safety line being secured to an attachment secured to said roof surface gripping means which is maintained at a disengaged position by a spring restoring means; and v) engaging said roof surface gripping means into said roof surface upon a load applied to said safety line overcoming a restoring force of said spring restoring means.
i) positioning a mobile roof safety device having a displaceable frame with a weighted base on said roof;
ii) displacing said mobile roof safety device to a safe position of use;
iii) retracting frame displacement means to lower said weighted base on said roof;
iv) attaching a safety line to an actuable roof surface gripping means secured to said weighted base, said safety line being secured to an attachment secured to said roof surface gripping means which is maintained at a disengaged position by a spring restoring means; and v) engaging said roof surface gripping means into said roof surface upon a load applied to said safety line overcoming a restoring force of said spring restoring means.
22. The method as claimed in claim 21, wherein there is further provided the step of attaching a further safety line of predetermined length to a connecting means immovably secured to said displacement frame, said weighted base when in contact with said roof and said further safety line restricting the displacement of a worker secured thereto within a restrained work zone delineated adjacent said mobile roof safety device and spaced from peripheral edges of said flat roof surface.
23. A method as claimed in claim 21 or 22, wherein said displacement frame is provided with retractable wheel assemblies pivotally secured to said frame, and displacement means to displace said retractable wheel assemblies form a roof surface engagement position wherein wheels of said retractable wheel assemblies exceed a lower surface of said weighted base for displacing said mobile roof safety device as in step (ii) and to a wheel retracted position where said wheels are positioned above said lower surface of said weighted base.
24. The method as claimed in any one of claims 21 to 23, wherein said step (ii) comprises displacing said mobile roof safety device by the use of a tow handle having a pivotal fork end secured to support arms of a front wheel of a frontal retractable wheel assembly, said pivotal handle being displaceable to a wheel engaging position wherein said fork end is in engagement with a surface of said front wheel to arrest said mobile roof safety device on said roof surface with said front wheel at said roof surface engagement position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2773376A CA2773376C (en) | 2012-04-04 | 2012-04-04 | Mobile roof safety device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2773376A CA2773376C (en) | 2012-04-04 | 2012-04-04 | Mobile roof safety device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2773376A1 CA2773376A1 (en) | 2013-10-04 |
| CA2773376C true CA2773376C (en) | 2019-06-18 |
Family
ID=49289830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2773376A Active CA2773376C (en) | 2012-04-04 | 2012-04-04 | Mobile roof safety device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2773376C (en) |
-
2012
- 2012-04-04 CA CA2773376A patent/CA2773376C/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CA2773376A1 (en) | 2013-10-04 |
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| EEER | Examination request |
Effective date: 20170403 |